Underfeed stoker



Ncv. 24, 1925- A. H. BLACKBURN ET Al.

UNDERFEEDVSTOKER Nov. 24,1925. l1,563,008V

A. H.- BLAKBuRN ET A1.

UNDEREEED STOKER Filed April 9; 1923 4 Sheets-sheet s |l// N m w. xm. XN. QN Mh NN kw M .1@ N Q\ Wh M@ f 775/775519/ MX Nov. 24,1925. 1,563,008

- A. H. BLACKBURN ET AL.

UNDERFEED STOKER Filed April 9, 195. 4 sheets-sheet. 4

WZ-f

Patented` Nov., 24, 1925. l

UNITED sTATEs l v'1,:5634198 PATENT oEEICE.

ARTHUR H. BLACKBURN, OF WORCESTER, MASSACHUSETTS, AND SAMUEL A. ARM- STRONG, OF DETROIT, MICHIGAN, ASSIGNORS, MESNE ASSIGNMENTS, T0 RILEY STOKER CORPORATION, OIE'- WORCESTER, MASSACHUSETTS, ACORPORATION 0F MASSACHUSETTS.

UNDEBFEED sroxnit.

y f applicati@ mea April 9, 1923.- seriai No. 630,990.

To all whom t may concern.'d 4

Beit known that we, ARTHUR H. BLACK- `BURN and SAMUEL A. ARMSTRONG, subjects of the King of Great Britain, residing, re-

spectively, at Worcester, in the .county cf 'Worcester and State o f Massachusetts', and

at Detroit, in the county of Wayne and Stato of Michigan, have invented certain new and useful Improvements in Underfeed Stokers, of which the following is a specification.

Our invention relates to improvements 'in .underfeed stokers and more particularly to heavy duty stokers, in which the coal co'ns'umptionA rate must be hi h and the quantity 15' of coal handled vmay be arge in relation to .the stoker area.

It is now known practice to construct a Stoker wherein a plurality' of parallel-retorts,

" known as lateral retorts, 'are arranged at right angles to a longitudinal main retort,

.to receive their fuel supply from the main retort, the main lretort only being equipped with a rain. or other suitablemeans for the introduction of fuel fromthe fuel hopper, the distribution lof fuel from such hopper through the area served by the lateral retort affording a relatively large-rebed. e

One of the objects of our invention is to `provide a lateral retort Stoker for heavy duty, wherein the amount of fuel handled may be large, and the introduction and distribution thereof may be advantageously eff'ected in such a way as to involve only minimum tendency of the fuel to mass, choke,

bridge, or form clinkers, in any way to militate a ainst eilicient combustion; and at the l same time to improve the `feeding action and combustion characteristics and air distribution for heavy service. f

These and further objects which will become apparent to, those skilled `in the art' 4from the following description, taken in conjunction with the accompanying drawings,

we attainy` the construction hereinafter pointed out and claimed, but it will be understood that while we have illustrated in the Idrawi'n s for the purposes of disclosureonly a sing e yembodiment of our invention,

' changesin many matters `of construction and arrangement may benade without de art-ure from the spirit of our invention wit inthe of the appended claims. n the drawings, Fig. 1 is'al transverse vertical section' through a Stoker embodying our invention, taken on line 1-1 of Fig. 2;. Fig, 2 is a plan view, with parts broken away; Fig. 3 is a longitudinal vertical section on line 3 3 yof Fig. 2; and Fig. 4 is ay fragmentary View of the furnace front.

I n our improved Stoker we provide a ,plu-v rality of .longitudinally extending main retorts having acentral group, each of these main retorts having independent fuel-supply mechanism, so that, as between these main retorts a very large quantity of fuel may be handled while maintaining relatively small capacit of each retorta-nd consequent low deman on the feeding and distributing mechanism appurtenant thereto, thus to prevent expensive and otherwise undesirable enlargement'pf the equipment unit, and to prevent stoppage or breaking of onefuel feed ing mechanism from putting the entire furnace out of commission. The longitudinal retorts of this central group are arran d with their adjoining margins somewiit spaced apart for air passage therebetween, and tuyre structures span between adjoining margins o@ such retorts, to supply air toward both of the adjoining' retorts. Flanking the extreme ones of the longitudinal main retorts are two groups of lateral retorts, each group comprising a. plurality of retorts, tuyre-equipped at their margins, havin their receptive ends arranged to revceiveV uel from thev respective extreme main retorts, and preferably havin their mouths laterally down-sloping towar dump'strucl tures extending along the sides of the firebox floor.

In the cxemplilication shown 10 and 10 indicate hoppers' for the greenpfuehv from which coal` may be fed b rams-11Y and 111', independently operab e', `through the feed throats 12fand12 intotwo parallel Vlongitudinal main retorts 13 and y13" which pare preferably arranged with Ytheirrnouths retorts arranged side by side and extending generally transversely with respect to the line of the main retort, with the side walls of` adjoining lateral retorts spaced apart to form air trunks 19 surmounted by the late"- erally extending tuyre structures 20 and 20.

.lateral retorts supplied therefrom, may

be variedbutf0r somepurposes itis preferable to form in the outer wall of each ex` treme main retort side-openings 21 between side-posts 22, and to arrange the receiving ends of the respective lateral retorts to communicate directly with the respective main retorts through these openings. The tuyremargined mouths of the lateral retorts 18.

preferably lie inra plane downsloping some.-

`What from the level of the main retort tu? yeres to the delivery end of the lateral retorts, and the bottoms 24 of the lateral retorts are preferably each formed with an up-sloping delivery end portion 25 and a Hat receiving end 26, horizontally disposed. The bottomsof the lateral retorts at the receiving end, are preferably lower than the fiat bottom 27 of the main retort which supplies fuel thereto, and the lateral retort bottoms find effective continuation in channels 28 formed in or below the main-retort bottom. n

Fuel-distribution means are p referabl provided in each lateral retort, and wit lateral retorts 0f the tw'o opposite groups arranged in aligning pairs, the distribution means for the two opposed retorts of such a pair may be united for operation in common. Thus, 29 represents pusher blocks in lateral retorts 18, arranged in the lflat bot` tom portions of the latter and connected by barY portions 3Q with corresponding blocks 29"in the respective retorts 18', such bars extending through the channels l28 afore` said and throu h apertures opening into the Wind-trunk 15 nt substantially filled by the bars. Each said bar may be reciprocated by connection of its depending finger 31, through a link 32 with a corresponding rocking lever 33 on arock shaft 34 that extends longitudinally of the structure and through the furnace front for exterior operation by a .suitable crank 35,' which ma ,be operated by a prime mover 36 indepen ently of or zin timed relation to the operationsof the feed- 1n rams.'

nel .distributin means are preferably provided. alsoin t e main longitudinal retort to further the' feeding action of the supply ram, s'uch'distribut1ng means nected to its respective ram by a lost motion "connection shown as involving adjustable stoppins 39 between which there works the ram-arm 40 to reciprocate the feed plate with a varying degree of lost motion.

rl`he fire-box iioorl may be completed by end-plate structures 41 and 41 flanking the delivery ends of the lateral retort group and down-sloping to the dump platforms 42, 42 which extend substantially to the respective furnace -side walls 43 and 43', thus, separating the combustion space 44 above the floor from the space below the floor which is divided into lateral ash pits 45, 45 and its central wind-box 46, to which air chamber air under pressureis supplied from any suitable means not shown. The partition separating the Wind-chamber and ash pits may comprise partition plates 48, between which there span the cross-beams 49 which centrally support the retort structure, the margins of the lateral retorts being carried on'longitudinal stringere 50. These plates 48 may also support the rock shafts 51 and 51, extending through the front of the furnace for manual operation, and upon which the dump platforms 42, 42 X are mounted. 95 Adjacent the front Wall 53 and the bridge wall 54, high, deeply sloped tuyres 55 may be employed at the extreme margins of the lateral retort group to Vprevent clinkering and maintain freedom of distributive feed.

Inl operation, it will be observed, the quantity of coal handled ma be very large, Without unduly loading eit er' feed mechanism, and while maintaining the coal in relatively small bodies in cross-'sectional area in all 105 portions'of the Stoker, so as to prevent or `minimize packing,`bri'dging, and lumping of the coal. Throughout all of the areas distributivefeeding tends strongly to revent v the. formation of surface clinkers deltiimental to the adequate passage'of air through the fuel in combustion, and the provision of independently operatable. feeding devices for the plurality ofl main re'tortsadmits of selective operation, so that thelfeed rams and their associated distrlbutingV means to the main retorts, may be operated either simultaneously or '.nonsimultaneously, with quite different eiectsas 'to the lifting and breaking of the central mass of comlamstibles spanning over theI central, uninterrupted tuyre'wall 16.

1. In an underfeed Stoker, the combination of a plurality of longitudinal main re-.125 torts forming anentral group, spaced apart and havinggtuyre structures spanning their adjoining, margns,`and vtwo groups of laterally-extending retorts flanking the extreme onespof said central retorts, eachlsaid laterally extending retort communicatingV with the adjacent Lone of said central retorts below the level of said tuyre structures .-to receive from such central retort fuel not yet in state of combustion," saidA laterallyextending retorts res ectively having `marginal tuyres, means or feeding fuel longitudinally along said longitudinal main re-` torts and means, below the level of said tuyres, for feeding fuel not y t in combustion laterally alongsaid laterally extending retorts. f v

2. ln an underfeed Stoker, the combination of a plurality of longitudinal main retorts forming. a central group, these being 4vspaced apart and having tuyre structures spanning their adjoining margins, two groups laterally extending retorts flanking the extreme ones of said central retorts and arranged to\r'eceive fuel therefrom, and independent meansA for introducing fuel into each-of the said kextreme longitudinal retorts.

, 3. 4ln an underfeed Stoker, the combinaf tion of a plurality of longitudinal main retorts forming a central group, spaced apart and having tuyre structures spannin their adjoining margins in` uninterrupted line, the extreme side walls of said group of longitudinal tuyeres having lateral openlngs therethrough, and two groups of laterally extending retorts, each group comprising a plurality of retorts spaced apart and having tuyre structures spanning between their ad'- joining margins and at their receptive ends` opening through the respective side openings of said extreme longitudinal retorts, to

v receive fuel therefrom, and independent means for introducing fuel into each of said rextreme longitudinal retorts.

4. I n an underfeed Stoker, thecombination of two longitudinal main retorts arranged in substantial parallelism with their mouths substantially horizontal and, withl their adjoining side walls spaced apart to provide an air passage therebetween, tuyre structures mounted on the adjoining margins of said main retorts, and two groups of laterally extending retorts. each group comprisin a plurality of such retorts arranged with t ieir mouths down-sloping away from the'lnain retort and with their side walls spaced apart to provide air passagestherebetween, and tuyre structures' mounted on the adjoining 'margins of said lateral retorts, the inner or receiving ends ofthe lateral retorts of 4each group being arranged to receive fuel from the adjoining one of said longitudinal retorts, independent means for feeding /fuel to each said longitudinal rebetween, and tuyre structures mounted on the adjoining margins of.- said lateral retorts, the inner or receiving ends of the lateral retorts ofeach'group being arranged to receive fuel4 from the adjoining one of said longitudinal retorts, and independent means for feeding fuel' to each said longitudinal retort.

"ARTHUR H. BLACKBURN. `SAMUEL A. ARMSTRONG.- 

